Yes, while more emphasis is always placed on the draft or on the injury-plagued playoff weeks, the middle of the season is the most crucial time of the year. Without vigilance and deft roster management through the bye weeks, no one has a chance at fantasy gold.

With that in mind, here are last-minute roster moves you should consider for every position on your fantasy roster.

Quarterback: Start Andrew Luck

While every fantasy player knows plenty about Robert Griffin III, the player who was selected above him in the real draft hasn't gotten nearly as much love.

This week, perhaps that should change.

Luck gets to face off against the league's 31st-ranked pass defense as he takes on the Cleveland Browns, and he's going to do so with Vick Ballard as his running back. Yes, Joe Haden is back, but there are plenty of other places to take apart that defense, and Luck has shown the presence of mind and the decision-making to do so.

Running Back: Start C.J. Spiller

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Buffalo is matched up against Tennessee's 24th-ranked rushing defense, and that should mean a good day for both C.J. Spiller and Fred Jackson. The exact split of carries has vexed fantasy owners all season (as have nagging injuries for both), but Spiller is the more dynamic of the two and has more game-breaking ability.

More importantly, this game should be close, as both teams struggle to stop opponents, and that should mean more opportunities for Spiller at the end of the game.

Wide Receiver: Start Denarius Moore

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The Raiders host the Jacksonville Jaguars this weekend—a defense that has been battered and broken this season along with a team that is looking more and more like its season is over. This team should be blown up, again, following the season, and this weekend could be the straw that breaks the Jaguars' backs.

Oakland hasn't had the best passing offense this season (ranked 21st), but they are built around speed and facing a defense that doesn't have much of it. Blown assignments are going to rule the day, and look for Moore (leading the team with 35 targets) to capitalize.

FLEX: Start Santana Moss

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The New York Giants may have a great pass rush, but they've also given up a lot of passing yards this season. Look for this game to be a shootout and for Santana Moss to be a big part of the 'Skins passing attack with Pierre Garcon banged up and possibly out.

Moss was also a bit of a "Giant Killer" last season, and remember that the Redskins beat their rivals twice.

This play isn't for everyone, obviously, and the suggestion isn't to start him as your WR1. But it's a week full of great receivers on byes, and one could certainly do a lot worse for his FLEX play this week.

Tight End: Start (or Pick Up) Dustin Keller

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Dustin Keller has been a fantasy nobody this year and isn't even owned in 10 percent of ESPN leagues right now. He's starting in only 5.2 percent. So, chances are many of you are only carrying one tight end and it probably isn't Keller.

However, if you're double-checking your roster and notice you've got a bad matchup (or even your lone tight end on bye), consider picking up Keller for this week, because he could pay dividends.

Keller is starting to get over the hamstring injury that has kept him sidelined and bottled up this season, and he has a long history of good games against the Patriots. Yes, the Patriots defense is much-improved this season, but that could also mean that Mark Sanchez will curl up in his security blanket and that Keller could see a lot of targets.

Kicker: Start (or Pick Up) Jason Hanson

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By average, Hanson is the best fantasy kicker this season. He's also the exact opposite of a fluke kicker; he's been doing this for years. He could literally miss every kick for the next 10 weeks, and the Lions would still stick by him. To some extent, he is the most revered Lion this side of Barry Sanders.

Yet, for some reason, he's starting in fewer than half of ESPN leagues.

Go get him and start him this week against the Chicago Bears. The Lions have a nasty habit of not putting the ball in the end zone, and that should continue against the Bears pass rush. The Lions will need Hanson's leg early, often and from deep to win this game.

The only caveat here is weather. Check the weather forecast for Monday night before inserting Hanson into your starting lineup. Still, Hanson has kicked in Soldier Field a number of times, many of them in inclement weather. It's not like he hasn't been there before.

Defense: Minnesota Vikings

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John Skelton hops aboard the Arizona Cardinals quarterback carousel against a Minnesota defense that has been licking its chops for a week. With ears firmly pinned back, the Vikings are going to harass Skelton all day and beat that Cardinals offensive line like a bunch of rag dolls.

Michael Schottey is the NFL national lead writer for Bleacher Report and an award-winning member of the Pro Football Writers of America. Find more of his stuff alongside other great writers at "The Go Route."